Work feed



Dec. 12, 1944. B. GROB ET AL 2,364,969

WORK FEED 2 Sheets-Sheet 1 Original Filed Jan. 10, 1938 ATTORNEY Dec. 12, 1944. ,3, ($05 ET AL 2,364,969

WORK FEED Original Filed Jan. 10, 1938 2 Sheets-Sheet 2 INVENTORS Bf/VJAMl/V 6/9019 779500095 6180.5

ATTORNEY Patented Dec. 12, 1944 Benjamin Grob and Theodore Grob,

Grafton, Wis.

Original application January 1-0, 1938, Serial No.

Divided and this 1941, Serial No. 399,282

4 Claims.

This applicationis a division of our copending application, Serial No.184,164, filed January 10,

1938, which has matured 2,253,515.

The invention of this application relates to work feeding mechanism for power operated saws and the like.

One object of the present invention is to provide an improved work positioning and guiding mechanism for power operated saws andthe like.

Another object is to provide an improved work feeding mechanism for power operated saws which will effectively advance the work and ac commodate steering movements thereof without imposing objectionable lateral stresses on the saw blade. 7

Another object is to provide work feeding mechanism for power operated saws and the like in which the thrust by which the work is advanced is maintained along a line substantially coincident with the line of cut regardless of variations in angular position of the work piece relative to the saw blade.

Other more specific objects and advantages will appear from the following description of an illustrative embodiment of the present invention.

In the accompanying drawings:

Figure 1 is a front elevation of a power operated band saw machine equipped with a work feeding mechanism constructed in accordance with the present invention.

Fig. 2 is a side elevation.

Fig. 3 is a plan view of the work table of that machine.

Fig. 4 is a fragmentary sectional view of the work table, on a larger scale, showing one of a number of anti-friction devices included therein.

The band saw machine selected for illustration is fully described in our copending application hereinabove identified. It comprises a conventional frame In supporting an upper pulley ll into Patent No.

and a lower power actuated drum I2, respectively disposed above and below an appropriate work table l3. In this instance the saw blade I4 is in the form of a band trained over the pulley l I and having its ends wrapped about the drum l2 in such manner that during operation one stretch of the band follows a fixed path downward through a predetermined point in the work table so that a work piece on the table may be sawed by advancing the same against the forward edge of the downwardly travelling band. As fully disclosed in said above identified application, the leading end: of the saw band may be detached application June 23,

from the drum l2 to permit the same to be threaded through an opening in the work piece preparatory to making an internal saw cut therein.

The machine shown is equipped with a work positioning, guiding and feeding mechanism embodying the present invention and which will now be described. This mechanism, as shown, includes a work carrier in the form of a slide plate l5 closely guidedin a channel l6 formed in the face of the work table l3 and extending parallel to the faces of the saw blade I4 and consequently parallel to the lineof cut. The plate [5 carries a bar I! adjustably seated in a narrow guide channel l8 formed in the face of the plate l5 and extending parallel to the channel It and along the-line of cut. The bar I! is so disposed that its central longitudinal axis is disposed within the central plane of the saw blade, the bar I! and plate 15 being slotted, as at l9, to

accommodate the saw bladeduring travel of the plate l5 in its guide I6, The bar I! is longitudinally adjustable in the channel [8 andmay be fixed in various positions of adjustment by appropriate means, such as a removable lockpin 20 therein engageable with any of a series of holes 2| formed in the base of the channel.

The bar I"! carries a thrust element 22 in the form of a small sprocket gear journalled on a pin 23 fixed in the bar. The sprocket gear meshes with a sprocket chain 24 encircling the work piece a and tightly secured thereto by appropriate means such as a clamp bolt 25. It will of course be understood that the work piece a may beof any shape or size within the capacity of the machine, that shown being a sample which is being internally sawed, the saw blade having been initially entered through an opening I) and having produced a partial saw cut 0 therein by advancing the slide plate l5, bar l1, sprocket gear 22, and work piece toward the right in Fig. 3.

It will be noted that the center of the sprocket gear 22 is disposed within the plane of the saw blade, so that as the carrier plate I5 advances, the advancing thrust transmitted to the work piece through the gear 22 is always in line with the cutting progress of the saw. It will also be noted that, so long as the gear 22 is fixed against rotating, it coacts with the chain 24 and with the saw blade to hold thework piece against turning, so that the progress of the out then follows a straight line course. It will also be understood that by rotating the gear 22 in one direction or the other. the work piece may be thereby turned in either direction about the cutting edge of thesaw blade to thereby cause the saw to depart in one direction or the other from its normal straight line course through the work, and during such steering movements of the work piece the gear 22 remains in line with the saw blade, so that the advancing thrust transmitted thereby to the work piece remains at all times in line with the cutting progress of the saw.

Rotation of the gear 22 may be controlled in various ways, but in the machine shown this is accomplished by the use of a segmental gear 26 meshingwith the gear 22 and journalled upon a pin 21 fixed in the bar IT. The gear 26 is preferably manually controlled by an appropriate lever 28 rigidly connected thereto and equipped with a convenient operating handle or knob 29. The lever 28 may be releasably fixed in any position of adjustment by appropriate means, such as a clamp screw 30 carried by the bar I! and coacting with a slotted quadrant 3| on the lever.

Although the carrier slide l5 may be manually advanced to advance the work piece against the saw blade in the manner above described, provision is made in the machine shown for effecting automatic advance thereof. The means shown for that purpose is designed to maintain a predetermined thrust of the work against the saw and for that purpose it is gravity actuated. It comprises an actuating and control lever 32 rockably supported, as at 33, on the base of the machine and having a plurality of weights 34 removably and adjustably attached to one end thereof. The lever 32 is provided at its other end with a conveniently arranged pedal 35 rockably mounted thereon and connected to operate a depending latch 36 disposed to engage an anchor pin 3! 'on the base of the machine in a manner to releasably sustain the weighted end of the lever 32 in elevated position, a position assumed preparatory to a sawing operation.

A cable and pulley system provides a convenient operating connection between the weighted lever 32 and the carrier slide I5. In this instance a cable 38, attached at one end 39 to a pin projecting from the bottom of the carrier slide l5 and through an appropriate opening in the channel l6, is trained over a pair of guide pulleys 40 and 41 on the work table l3, beneath a supporting pulley 42 on the lever 32, and about a pulley 43 adjustably mounted on a vertical guide bar 44, the other end of the cable being attached to a slide block on the guide bar below the pulley 43. The vertical guide bar 44 is fixed to the side of the machine frame adjacent and above the lever 32. The slide block 45 is limited in its upward movement along the bar 44 by a stop element 46 constituting part of a switch member 41 attached to the machine frame and forming part of a safety control system fully disclosed in said above identified copending application but constituting no part of the present invention. The slide block 45 is, during a sawing operation, retained in contact with the stop element 46 by the tension in the cable. The pulley 43 is vertically adjusted and controlled by appropriate means such as a lead screw 48 journalled in a suitable bracket 49 fixed on the guide bar 44 and threaded through the slide block 50 on which the pulley 43 is mounted.

In preparing for a sawing operation the thrust bar I! is ordinarily initially set in retracted position in the retracted carrier slide l5 with the steering lever 28 fixed in the intermediate position shown, and the work piece, with the chain -24 clamped thereon, is then placed in preliminary sawing position on the slide l5 with the chain 24 engaged with the thrust gear 22. With the weighted lever 32 fixed in the upper position shown by the latch 36 and pin 32, the screw 46 is operated to lift the pulley 43 and thereby take up all slack in the cable 38 and position the slide block 45 against the stop element '46. Then after the saw blade I4 has been set in motion, the pedal 35 is rocked to release the latch 36 from the pin 31 and thereby release the lever 32, whereupon the carrier slide I5 advances under the force transmitted from the weights 34 through the cable 38, and the work piece is thereby fed against the saw by the thrust imposed through the gear 22.

The sawing then normally proceeds along a straight line course as the work is advanced with the carrier slide I5 along the guideway l5, but if it is desired to depart in one direction or the other from that course, this is accomplished by releasing and swinging the steering lever 28 and segmental gear 26, so as to rotate the pinion 2! and thereby cause the work to swing in the desired direction about the cutting edge of the saw blade.

The progress of the sawing operation may be interrupted merely by depressing the pedal 85 so as to release the tension in the cable 36, and at the end of the sawing operation the pedal 35 is depressed sufliciently to permit re-engagement of the latch 36 with the pin 31.

If the length or the desired saw cut is greater I than can be effected in one downward movement of the weights 34, the operation may be repeated,

the work piece being, when necessary, set forward on the carrier slide l5 by advancing the bar l'l along its guideway l8 into a new position of adjustment therein, or the weights 34 may be re-elevated by adjusting the pulley 43 to a higher position on the guide bar 44.

In order to permit the work piece to turn freely about the cutting edge of the saw blade whenever the steering lever 26 and gear 22 are rotated, so as to relieve the saw blade of objectional side stresses. an appropriate anti-friction work support is preferably provided. In the machine shown this is accomplished by the use of a plu rality of anti-friction balls 5| counter-sunk at rather regiilar intervals in the top faces of the work table l3 and carrier slide I5. As indicated in Fig. 4, each-ball 5| rests upon a circular series of balls 52 confined in the bottom of a cup-shaped bushing 53. Each bushing is supported by a top flange 54 and is locked in place by a suitable retainer ring 55. Each ball 5| projects slightly above the bushing into work engaging position and is retained by a ring 56 seated in the top of the bushing.

It will of course be understood that during the sawing operation the degree of feeding pressure between the saw and work is determined by the size and position of the weights 34 upon the lever 32, and that they may be regulated as desired to best suit the particular piece of work being operated upon. In any case however the work is thus advanced at substantially constant pressure which is a highly desirable condition, except that unless provision be made to prevent it, the work will jump ahead suddenly whenever th saw breaks through at an end of a cut or whenever, as in some cases, the saw suddenly enters an opening in the work piece. Such jumping is objectionable and a common cause of damage to the saw, and in the machine shown provision is mad to prevent it. In this instance this is accomplished by the use of a well known type of dash-pot mechanism 51 of a direct single acting piston-and-cylinder type, the cylinder thereof being rockably connected at one end 58 to the lever 34 and the piston rod 59 being rockably connected at 50 to the frame of the machine. The dash-pot shown functions to permit free upward movement of the weights 3!! but to resist rapid lowering thereof.

Various changes may be made in the embodiment of the invention hereinabove specifically described without departing from or sacrificing the advantages of the invention as defined in the appended claims.

We claim:

1. A work feeding mechanism for power operated saws and the like, said mechanism comprising a work holder, a carrier guided for rectilinear movement, and an element for applying a feed thrust to the work andmoveable with said carrier to feed the work against the saw, said element being rotatable about an axis disposed substangear being engaged with said chain to feed the work against the saw and to regulate the angular position of the work relative to the saw.

3. A work feeding mechanism for power operated saws and the like, said mechanism comprising a carrier guided for rectilinear movement, actuating means therefor, a work holder, a work thrusting element coacting with said holder and .moveable with said carrier to feed the work against the saw, said element being rotatably adjustable during the feed movement to steer the work relative to the saw, and means for adjusting said element relative to said carrier in a direction toward and from said saw to accommodate the same to various kinds of work.

4. In a machine of the character described, the combination of a table having a work supporting surface, a cutting tool extending through said table, a slide guided in the top of said table for rectilinear movement, actuating means for said slide, a work holder, an element carried by said slide and coacting with said work holder to feed a work piece toward said tool, said element being mounted for angular adjustment about an axis fixed relative to said slide, and means for angularly adjusting said element during the feed movement to thereby angularly adjust the work piece relative to said tool.

i BENJAMIN GROB. THEODORE GROB. 

